The present invention relates generally to the field of mobile communication devices and deals more particularly with a package and housing design that combines the mechanical design considerations for the RF and acoustic functionalities to reduce the overall physical size of the device and enhance accoustic performance.
The growth in the use of portable electronic devices such as, for example mobile communication devices, cellular telephones and the like, has driven the design of such devices to become smaller and more convenient. Consumers have become accustomed to the convenience and portability of such electronic devices, particularly, cellular telephones and have demanded that those cellular telephones become even more convenient and even more portable. The constant thrust in cellular telephone design is to make them as small as possible. One way that has resulted in a reduction in the size of the cellular telephone housing has been to reduce the size of the battery pack powering the device. However, the reduction in the size of the device based solely on reduction of battery size is not sufficient to meet the requirements of providing very small or smaller devices than currently available.
There is also an increasing demand that mobile communication devices operate in a xe2x80x9chands-freexe2x80x9d mode, that is, the device is operational without holding it up to the user""s ear. The increased demand for xe2x80x9chands-freexe2x80x9d operation is due in large part to safety considerations, particularly for example, when operating a motor vehicle and the like and attempting to carry on a conversation. An increasing number of jurisdictions are attempting to regulate and control the usage of mobile communication devices while operating a motor vehicle and thus there is a need to provide such xe2x80x9chands-freexe2x80x9d operation. The desire for xe2x80x9chands-freexe2x80x9d operation of the mobile communication device demands that the acoustic performance and characteristics be enhanced to improve audio and sound quality to hear the received audio without holding the receiver to the user""s ear.
Conventional and commonly known and used mobile communication devices generally include an internal antenna and a speaker component. The mechanical design and operational considerations for the antenna and speaker must be taken into account to insure the proper operation of each to obtain the desired results. The internal antenna includes an RF-emitter that is generally held or located in a spaced separation with respect to a ground plate mounted in the chassis of the device. The RF-emitter electrically connects to the operational electronic circuitry of the mobile communication device and the spaced separation between the RF-emitter and the ground plate area defines the mechanical outline of an antenna chamber volume.
The speaker component is located separate and away from the RF-emitter to prevent interference with the emitter. It is a current requirement that the speaker component provide a sufficiently high air displacement and pressure to produce audible sounds loud enough to implement a xe2x80x9chands-freexe2x80x9d operation. Typically, the speaker is mounted in an enclosure of some sort defining a chamber which functions as an acoustic resonator to enhance bass-tone production. The physical size or volume of the chamber influences the audio quality, and a larger volume generally results in better audio quality. A drawback with traditional speaker components meeting these requirements is their large physical size. Improved speaker components that are physically smaller in size than the traditional speaker components and having comparable performance have been developed however, these newer speakers require a xe2x80x9ccontrolledxe2x80x9d back cavity to operate properly. Providing the back cavity to allow usage of these improved speaker components would require the mobile communication device to become larger in size rather than smaller. As a result, both the internal antenna and the speaker component impose separate mechanical design requirements that add to the overall physical size of the mobile communication device.
Therefore, there is a need to identify further construction methods and designs that provide the desired overall physical size reduction and yet provide a chamber having a desired volume to enhance acoustic characteristics and performance of the speaker component of a mobile communication device.
Accordingly, it would be desirable to have the antenna and speaker share at least a portion of the volume required for the antenna to provide the RF functionality, with the speaker to provide the acoustic functionality of the mobile communication device to further reduce the size of the mobile communication device.
Therefore, it is a general object of the present invention to provide a mechanical design that reduces the size of the mobile communication device.
It is a further object of the present invention to provide a design method to combine the RF functionality and accoustic functionality of the mobile communication device.
It is another object of the present invention to provide a reduced size mobile communication device by sharing a common physical volume for both the antenna and the speaker that accommodates the mechanical design requirements of the antenna and speaker, respectively.
It is a yet further object of the present invention to provide a reduced size mobile communication device wherein the antenna volume chamber provides the required back cavity for the speaker component.
In accordance with a first aspect of the invention, a mobile communication device of the type having a RF transmitter and receiver, a RF antenna and a speaker component includes a housing for carrying subassemblies comprising an operational communication device. The housing itself is generally a contoured case that has an exterior surface and an interior surface. The interior surface forms and defines an interior cavity within the housing for carrying both a speaker component and a RF antenna.
Preferably, the RF antenna is a planar antenna.
Preferably, the interior cavity is an acoustical cavity.
Preferably, the planar antenna defines an internal antenna for providing RF functionality.
In accordance with a further aspect of the invention, a mobile communication device has antenna functionality and speaker functionality and includes a housing for carrying subassemblies of the operational communication device. The housing has an interior cavity of a predetermined volume for providing the antenna functionality and speaker functionality.
Preferably, the interior cavity has a covering and a planar antenna is carried on a surface of the covering.
Preferably, the planar antenna is carried on an outer surface of the covering.
Preferably, the planar antenna is carried on an inner surface of the covering.
Preferably, the interior cavity is an acoustic resonator.
Preferably, the interior cavity has at least one acoustic leak hole for emitting sound produced by the speaker functionality.
In another aspect of the invention, a reduced size mobile communication device includes a housing for carrying subassemblies defining the operational communication device. Speaker means are provided for producing audible signals, and antenna means are provided for transmitting and receiving RF signals. Cavity means within the housing carry both the speaker means and the antenna means. Additionally, the cavity means defines a common shared chamber that functions as an acoustic resonator chamber and an antenna-ground plate separation chamber.
Preferably, the antenna is a planar antenna.
Preferably, the speaker is an audio transducer.
A yet further aspect of the invention relates to a method for construction of a mobile communication device having combined antenna and speaker component functionalities. The method for construction comprises the steps of: providing an antenna supporting structure having an outer wall surface generally transverse to peripheral walls extending therefrom; terminating the peripheral wall ends at the intersection with the surface of a ground plate thereby defining a first interior chamber volume between the outer wall, peripheral walls and ground plate; mounting and locating a speaker component between the ground plate and a wall surface of the communication device in a region generally defined by the projection of the outline surface area of the antenna supporting structure first wall and peripheral walls on the communication device wall surface; and providing means for communication between the first interior chamber volume and the speaker component to define a controlled volume back cavity to provide a larger volume acoustic resonator chamber for air displaced by the speaker component to enhance the acoustic performance of the speaker component without increasing the size of the mobile communication device.
Preferably, the method further includes the step of providing a substantially pressure-sealed first interior chamber volume.
Preferably, the method further includes the step of providing a printed circuit board for carrying electrical components defining the operational communication device and locating the printed circuit board within the first interior chamber volume.
Preferably, the method for construction further includes the steps of locating the printed circuit board in a spaced relationship between the first wall and the ground plate; sealing the seam defined by the peripheral marginal edges of the printed circuit board and the corresponding intersection of the inner surface of the peripheral walls of the antenna supporting structure; and providing means in the printed circuit board for communication between the first and second chamber portions created in the first interior chamber volume by the printed circuit board located therein, whereby air displaced by the speaker component communicates with the controlled volume back cavity defined within the first interior chamber volume.
Preferably, the method for construction further includes the step of providing a planar antenna on the first wall outer surface.